The present invention pertains to target detection and particularly to active sonar target detection. More particularly, the invention pertains to active sonar target detection with phase quieting.
In the related art, detection with active sonar in targeting is typically done by magnitude thresholding. Coherent receivers are used in beam-forming; but phase information, which is available with electronically steered beam sets, is not fully utilized in the target detection process.
The capabilities of detection systems to detect, localize and track submarines and other submerged vehicles is a great strategic significance. In recent years, many advances in naval technology have resulted in the development of acoustically quieter submarines, in that they radiate less and reflect less sound energy than their predecessor submarines.
The use of a sonobuoy and a torpedo to detect and track a potentially hostile submarine employs both active and passive acoustic detection. The choice of one detection mode depends on strategic factors as well as the magnitude of radiated noise of the submarine in question. For instance, if a potential target produces no measurable radiated signal in the sonar receiver, then it becomes necessary to involve active detection processing, that is, to acoustically illuminate the ocean to find the potential target.
Active acoustics will play a greater role as quieter submarines evolve. Future active sonar detection systems will need to be maximally sensitive and accurate. Utilizing both the magnitude and the phase of the acoustic return signal is important in meeting such need of more effective detection.